Metal rolling mill



Patented oct. 11, 193e UNITED Y STATES PATENT OFFICE METAL ROLLING MILL Claude A. Bollinger,` Gary, Ind.

`Application March 24, 1937, Serial No. 132,823 i claim. (ci. zio-31.1)

This invention relates particularly to the joining of metal .strips in vsuperimposed relationship by passing them through a set of pressure rolls while providing suflicient heat to eiect interweld- 5 ing, but the broad principles of the invention are applicable to many metal rolling problems. The primary object is to prevent slipping of the strips either relative one another or relative the rolling surfaces necessarily involved.

l Another object of practically equal importance is to roll the strips together so that they are respectively brought into' complete contact with each other.

Still other objects may be inferred from the l followingdisclosure.

In the accompanying drawing:

Figure 1 is a sectional elevation of a mill embodying the principles ofthe present invention.

Figure 2 is apartially sectioned view showing 20 the roll elements of this mill.

The mill includes a housing I which mountstwo parallel rotary mandrels 2 having journals 2a and fiuted ends `2b. These mandrels 2 are rather similar to metal rolling rolls, the jourbeing adapted for connection with powered spindles.

30 However, these mandrels 2 differ from ordinary rolling rolls in that they have circumferentially grooved surfaces, these grooves being marked 2c in the drawing, and in that they work through a set of hollow rolls 4 which encircle the 35 mandrels', these rolls being internally grooved to provide grooves 4*L which t the grooves 2c of the mandrels. The rolls 4 have inside diameters which are larger than the outside diameters of the mandrels 2, whereby the rolls 4 rotate 40 eccentrically respecting the mandrels 2 when they are pressed together by the operation of theholddowns 3. The diameters of the respective parts should be related so that the rolls 4 may be slid freely over the mandrels 2 when this is neces- 45` sary, it being obvious that the inside diameter of the rolls must be sufficiently large topermit clearance between the various grooves.

In the embodiment of the invention under discussion, three strips are being welded together.

50 The inside one of these strips may be commer'- cially pure iron, while the outside strips may be' copper, nickel or an alloy, or any of the 4other metals commercially used in the production of multiple-layer strip.

55 Guides 5 lead the iron strip straight through the pass of the rolls 4'and in a plane with the same, from a furnace 6 (of which only the vend is shown), then over a deilector roll 1 and so to a tension reel 8. Suitable means for driving this reel 8 so as to apply proper tension are l known to those skilled in the art.

The outside metal strips are fed from coil boxes 9 which are oilset relative the pass line of the rolls 4, through friction blocks Ill and from there tangentially onto the surfaces of the rolls 4, the 10 strips wrapping around these rolls throughv 180 degree arcs and eventually passing between them so as to be brought into contact with the middle strip. It now becomes obvious that the tension reel handles all three strips, the heat from the iron strip being sufficient to effect the welding.

According to the prior art, when the general operation under discussion is to be carried out, the strips to be joined are passed between solid rolling rolls very similar to, if not the same, as metal rolling rolls. Furthermore, all the strips -to be joined are fed through the rolling pass in at least approximately the same plane, this plane coinciding with the pass line of the rolls used. The above procedure is beset with two big difficulties, one of these being a decided tendency of the strips to slip, relative the working rolls and one another, while the other is the inability of the rolls to bring the strips into perfectly flat, complete contact with each other when they are fed in the same' common plane straight through the roll pass. It requires little imagination to realize'that both of these difliculties pref sent serious obstacles in the .way of obtaining a 35 product wherein the various stripsare integrally united in such a manner as to permit subsequent processing, such as cold rolling and the like, or their fabrication into ultimate products. this often involving drawing and forging effects. 40

Such difficulties are largely obviated by the invention under discussion. The rolls 4 rotating eccentrically respecting the powered mandrels-2 provide endless rolling surfaces that'are under the same rolling pressure and Have much the same motion as the strips, the latter therefore being imparted the same linear speed as the peripheral i speed of the rolls. Interposed friction-reducing films, such as are generally encountered in practice, are relatively immaterial.l The rolls 4 provide endless successions of continuously overlapping, progressively curved surfaces, as contrasted to the rolling surfaces of ordinary rolls. The contrast may be to some extent compared i i WWHHHM mrthermore, due t6 the strips being 1ed tan.

gentially ontc;E the roll* surfacesby means offset fromrthe pass line of the rolls, the strips Imust wrap at least partially around the roll surfaces prior to their being 4pressed into contact with the center strip. This, in conjunction with the feature of the eccentrically driven rollsff4, assures not only that no slipping will @our butL also, that the outside strips Willi'have conformed exactly to the cylindrical surfaces of the rolls prior to their being pressedonto the center or iron strip. This wrapping feature also provides time for the outermoststrips tY absorb a large amount of the h-.at from; the rolls- 4, it being remembered that the cent strip is heated and that heatL from strip .is being constantly absorbed by the rolls 4. Although the principles ofthe invention have be'en disclosed by means of a 'specific example'in accordance with the :patent statutes, itis not intended that its scope be thereby limited exactly to this example, except to the extent dened by thegappende'd claim. Iclaim:

mill characterized by a set of holiow rolls and mandrels passed through said rolls and provided with holddowns for applyinglpressure to said rolls,

the inside diameters of the latter being materially 

